Contrast enema in a 1.3-year-old boy with acute abdominal colics and a palpable abdominal tumor. Visible are the upper part of the descending colon and the transverse colon. Within the latter there is a stop of the contrast which was provided by the anus.
The diagnosis is an intussusception; the tip of the invagination lies nearly distally to the right colonic flexure. The intussusception allows some contrast to pass between the wall of the colon and the tip of the invagination. The shape of the contrast stop tells if the lumen of the colon is completely filled up by the tip of the invagination.
Sometimes the contrast may move into the uninvolved cecum and therefore, the filling defect in the ascending colon may be overlooked.